Summary: The University of Chicago animal research program has grown considerably in the last 10 years. The University has kept up with the growing animal census by renovating animal facilities and incorporating vivaria into three new research buildings. These new research buildings have significantly improved the quality of research and animal space available at The University. The Carlson Animal Research Facility is the largest and most significant facility on campus in that it supports the most diverse biomedical research studies. Carlson provides a significant proportion of the mouse barrier housing, biosafety (ABSL2) housing, and procedural space for rodents. It also provides non- rodent housing and is the only facility able to house large animal species. The Carlson facility is critical to the animal care program. Several renovations have been completed in Carlson to add and improve housing and research space in the last 10 years and the Carlson Facility is again preparing to expand animal housing capacity to support the University's new Neurosciences Institute. The function of the cage wash operation however needs to be addressed as part of this renovation. We propose to address this by replacing the washing equipment in the Carlson cage wash with newer more efficient machines. We have already initiated the replacement of the Carlson rack washer and with the funding of this proposal we will replace the existing tunnel washer. These two pieces of equipment have major repair issues and decrease the efficiency of the cage wash operation. Their replacement will significantly improve the operational efficiency of the facility, which will have a significant impact on our ability to provide high quality and efficient animal care.